Diaper fastener



FIG. 1 is a front view of the diaper fastener in the shape of a hand, with the diaper to which the diaper fastener is attached as shown in broken lines.

The broken line showing a diaper on which the diaper fastener is attached is included for the purpose of illustrating environmental structure and forms no part of the claimed design. The sides of the diaper fastener are flat and are not claimed. 

The ornamental design for a diaper fastener, as shown and described. 